Downhole multi-action jetting tool

ABSTRACT

An apparatus for cleaning a wellbore casing includes an outer housing having an axial through passage between an inlet and a first outlet wherein the inlet and the first outlet are adapted for connection in a work string, the outer housing having a second outlet extending in a direction generally transversely of the through passage, an index mandrel slidably located within the outer housing and having an axial bore extending therethrough, the index mandrel being movable relative to the outer housing between a first position in which the second outlet is closed and a second position in which the second outlet is open, a ball seat located on an upper end of the index mandrel, a spring located within the outer housing and biasing the index mandrel toward the first position, a ball retainable on the ball seat to prevent flow from the inlet to the first outlet, and wherein application of a first pressure on the ball forces the index mandrel against the spring into the second position and reduction of said first pressure permits return of the index mandrel to the second position.

This application claims priority to Provisional Patent Application60/695,828 filed on Jun. 30, 2005 and entitled, “Downhole Bypass Valve”the contents of which are incorporated herein by reference for allpurposes. New matter has been added.

BACKGROUND OF INVENTION

A wellbore may be drilled in the earth for various purposes, such ashydrocarbon extraction, geothermal energy, or water. After a wellbore isdrilled, the wellore is typically lined with casing. The casingpreserves the shape of the wellore as well as provides a sealed conduitfor fluid to be transported to the surface.

In general, it is desirable to maintain a clean wellore to preventpossible complications that may occur from debris in the wellore. Forexample, accumulation of debris can prevent free movement of toolsthrough the wellore during operations, as well as possibly interferewith production of hydrocarbons or damage tools. Potential debrisincludes cuttings produced from the drilling of the wellore, metallicdebris from the various tools and components used in operations, andcorrosion of the casing. Much of this debris may be removed byincreasing the annular fluid velocity to bring larger particles to thesurface of the wellbore.

However, over time, the casing or liner within the wellbore becomescovered with hard deposits. These deposits must be periodically removedor they can build up to levels of thickness and hardness where they canadversely affect efficient operation of the oil well.

Many tools operate continuously through a wellbore, for example scrapersand brushes. While it is useful to have such continuous use tools, it isoften beneficial to have tools that are selectively operable when thetool has reached a preferred location in the wellbore.

Cleaning involves spraying or jetting the inner wall of the casing withcleaning fluid at very high pressure to break up and dislodge thedeposited material. A cleaning device having side jetting nozzles islowered into the wellbore casing on the end of a drill string. Once asection of the wellbore casing has been jet cleaned, the cleaning deviceis withdrawn from the wellbore casing and removed from the end of thestring. The drill string is then returned to the wellbore casing andcleaning fluid is run through the casing to a point below the section ofthe wellbore casing that was jet cleaned. The cleaning fluid circulatesupward through the annulus between the wellbore casing and the drillstring, carrying material dislodged during the jetting operation to thetop of the wellbore casing. This operation of jetting and flushing isrepeated as necessary to clean the wellbore casing of depositedmaterial. Many cleaning and jetting tools use multiple balls to actuateand de-actuate the tool. It would be an improvement to have a cleaningtool that can be actuated and de-actuated without the need to usemultiple balls.

SUMMARY

In one aspect, the disclosed invention relates to an apparatus forcleaning a wellbore casing including an outer housing having an axialthrough passage between an inlet and a first outlet wherein the inletand the first outlet are adapted for connection in a work string, theouter housing having a second outlet extending in a direction generallytransversely of the through passage, an index mandrel slidably locatedwithin the outer housing and having an axial bore extendingtherethrough, the index mandrel being movable relative to the outerhousing between a first position in which the second outlet is closedand a second position in which the second outlet is open, a ball seatlocated on an upper end of the index mandrel, a spring located withinthe outer housing and biasing the index mandrel toward the firstposition, a ball retainable on the ball seat to prevent flow from theinlet to the first outlet, and wherein application of a first pressureon the ball forces the index mandrel against the spring into the secondposition and reduction of said first pressure permits return of theindex mandrel to the second position.

In another disclosed embodiment of the invention, a method of cleaningan inner surface of a casing in a wellbore includes lowering a jettingtool on a work string into the wellbore to a desired location, whereinthe jetting tool has an outer housing with an axial through passagebetween an inlet and a first outlet, the outer housing also having asecond outlet substantially transverse to the axial through passage, andan index housing slidingly retained within the outer housing in a firstposition such that the second outlet is closed, the index housing havinga ball seat on an upper end and being biased toward the first position,dropping a ball into the axial through passage to rest on the ball seat,thereby preventing fluid flow between the inlet and the first outlet ofthe axial through passage, causing fluid pressure to force the indexhousing to a second position wherein the second outlet is open,circulating fluid from the axial through passage and the second outletat a fluid pressure sufficient to clean the casing, decreasing the fluidpressure to return the index housing to the first position, increasingthe fluid pressure to move the index housing to a third position whereinthe second outlet is closed, and wherein the increased fluid pressure issufficient to shear the ball from the ball seat, thereby reducing thefluid pressure on the index housing causing it to return to the firstposition.

In another embodiment of the disclosed invention, a method of openingand closing an outlet through a side of a cylindrical outer housing of ajetting tool in a wellbore includes biasing the index housing to anupward position within the outer housing in which the index housing isblocking the fluid outlet through the side of the outer housing,dropping a ball to seal against a ball seat located at the upper end ofthe index housing and block fluid flow through the jetting tool, forcingthe index housing to a lower position inside the outer housing as aresult of increased pressure behind the ball, wherein the fluid outletthrough the side of the outer housing is open, reducing the fluidpressure on the ball to permit the biasing of the index housing towardsthe upward position, wherein the fluid outlet through the side of theouter housing is closed, and increasing the fluid pressure on the ballto a pressure sufficient to shear the ball through the ball seat,thereby permitting the index housing to return to the upward position.

Other aspects and advantages of the claimed subject matter will beapparent from the following description and the appended claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an embodiment of a well cleaningtool.

FIG. 2 is a front view of an embodiment of a well cleaning tool.

FIG. 3 is a detail cross sectional view of an embodiment of a wellcleaning tool.

FIG. 4 is a layout of an embodiment of an indexing groove.

FIG. 5 is a schematic of a well cleaning tool in a first, run-in-hole,position.

FIG. 6 is a schematic of a well cleaning tool in a second, jetting,position.

FIG. 7 is a schematic of a well cleaning tool in a third, intermediate,position.

FIG. 8 is a schematic of a well cleaning tool in a fourth, ball shear,position.

FIG. 9 is a partial cross sectional view of the downhole bypass valve ina first run in position.

FIG. 10 a is a partial cross sectional view of the indexing pin andsurrounding components.

FIG. 10 b is a partial cross sectional view of a port and a bonded sealmember.

FIG. 10 c is a partial cross sectional view of a collet assembly.

FIG. 11 is a partial cross sectional view of the downhole bypass valvein the first position with the ball actuator.

FIG. 12 is a partial cross sectional view of the downhole bypass valvein a second position.

FIG. 13 is a partial cross sectional view of the downhole bypass valvein a third position.

FIG. 14 is a partial cross sectional view of the downhole bypass valvein a fourth position.

FIG. 15 is a layout of the indexing groove.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a downhole jetting tool 100 that may be usedto selectively divert fluid that is flowing down the drill string bore102 to the annulus 104 between the drill string and the casing 106 of awellbore 108. The jetting tool 100 includes an outer housing 110 and aspring-loaded index mandrel 168 defining a tubular assembly having aninlet 206 and a first outlet 208.

The outer housing 110 defines an axial through passage 124 within whichthe index housing 168 is located. The outer housing 110 has a top sub126 provided at a top end 112, wherein the top sub 126 includes athreaded box 114 to couple to an upper drill string component (notshown). The top sub 126 has one or more radially extending ports 132extending from the axial through passage 124 to the annulus 104,collectively defining a second outlet 128. The top sub 126 is coupled toa swivel housing 116 for the index housing 168 at a lower end 130. Thecoupling of the swivel housing 134 and the top sub 126 provides an uppershoulder 138 at the lower end 136 of the top sub 126. A lower shoulder140, formed in the swivel housing 116, is spaced apart from the uppershoulder 136 to form an inner recess 142 within which a swivel ring 144is retained. The swivel ring 144 includes at least one indexing pin 146extending radially into the axial through passage 124 defined by theouter housing 110. While the swivel ring 144 is axially retained by theupper and lower shoulders 138, 140, the swivel ring 144 is notrotationally retained to the outer housing 110. Thus, the swivel ring144 may rotate within the confines of the upper and lower shoulders 138,140. Along a middle portion 150 of the swivel housing 116, a springhousing 152 is coupled thereto. A lower portion 154 of the swivelhousing 116 protrudes axially within a through bore 156 defined by thespring housing 152. The lower portion 154 of the swivel housing 116 isspaced apart from the corresponding portion of the spring housing 152such that a small gap 162 is created. Within this small gap 162, aspring sleeve 162 is coupled to the spring housing 152. As will beexplained below, the spring sleeve 164 is included primarily to aid inthe assembly and disassembly of the jetting tool 100. The spring housing152 is provided with external threads 120 at lower end 118 to coupled toa ball catcher 122 or another lower drill string component (not shown).

As previously stated, the index housing 168 is located within the outerhousing 110. The index housing 168 includes an indexing mandrel 170coupled at a lower end 172 to a collet blank 174 to define a mandrelthrough passage 176. The through passage 176 has a mandrel bore radius178. The indexing mandrel 170 has a ball seat 148 sealingly coupled at atop end 158. An o-ring 166 may be included to seal the interface betweenthe ball seat 148 and the index mandrel 170. Other sealing means knownin the art may be used. The ball seat 148 includes a lower shoulder 186,which rests against top end 158. A frustroconical section 188 at the topof the ball seat 148 provides a guide to direct a ball 250 (the ball 250and related features are shown in FIGS. 5-8) through the center of thethrough passage. A landing section 190 projects generally inward at thebottom 194 of the ball seat 148. The landing section 190 projects inwarda sufficient distance and angle to seat the ball 250 as will bedescribed. The radius 240 of the landing section 190 is thus smallerthan the ball radius 252. A seal member 180 is located above a shoulderformation 182 in the outer surface 184 of the indexing mandrel 170 andbelow the lower shoulder 186 of the ball seat 148. Below the shoulderformation 182, a recess 202 is formed in the outer surface 184 of theindexing mandrel 170. An o-ring 204 or other sealing member seals theinterface between the outer surface 184 of the indexing mandrel 170 andthe inner surface 192 of the top sub 126 below the recess 202.

An indexing groove 200 is formed into the outer surface 184 of theindexing mandrel 170 between the o-ring 204 and a lower end 172 of theindexing mandrel 170. The indexing pin 146, coupled to the outer housing110, is positioned within the indexing groove 200. The function of theindexing groove 200 and the indexing pin 146 is described in greaterdetail below.

A spring assembly 210 includes the collet blank 174, a spring follower214 and a spring 216. As was previously described, the collet blank 174couples to the index mandrel 170. The spring 216 is located within thethrough passage 156 defined by the spring housing 152. A shoulderformation 218 in the inner surface 220 of the spring housing 152 nearthe lower end 118 provides support to a lower end 222 of the spring 216.The spring follower 214 has a lower shoulder 224 that is seated atop anupper end 226 of the spring 216. The collet blank 174 has a lower end228 that is seated atop an inner shoulder 230 of the spring follower 214such that the lower end 228 of the collet blank 174 is within the springfollower 214.

The ball 250 will be used to actuate the jetting tool 100. The ball 250will be dropped from the top of the work string and allowed to floatdownward through the fluid in the axial through passage 124 until itreaches the ball seat 148. Thus, the ball 250 is formed from a materialhaving a specific gravity greater than fluid though which it will bedropped. Further, the ball 250 must be made from a material that willnot be degraded by the chemical composition of the fluid in axial thoughpassage 102. Also, when the jetting tool 100 no longer needs to becycled, the ball 250 can be sheared through the ball seat 148 byincreasing the fluid pressure through the axial through passage 102.Thus, the ball 250 is also formed from a material that will deform undera predetermined minimum pressure. For example, in one embodiment, theball is made from a thermoplastic polyester based on polyethyleneterephthalate, such as ERTALYTE (™).

When the jetting tool 100 is assembled, the spring 216 is lowered intothe spring housing 152 and the spring follower 214 is placed atop thespring 216. The swivel housing 116 couples to the spring housing 152.However, the length of the spring 216 when loaded only with the springfollower 214 would extend beyond the lower end 160 of the lower portion154 of the swivel housing 134 when the swivel housing 116 is coupled tothe spring housing 152. Instead of loading the spring 216 with theswivel housing 116 while coupling to the spring housing 152, the springsleeve 164 is coupled to the spring housing 152 to preload the spring216, through the spring follower 214, against a lower shoulder 166. Thesmaller size of the spring sleeve 164 makes it easier to couple to thespring housing 152 while simultaneously preloading the spring 216. Thelarger swivel housing 134 may then be simply coupled to the springhousing 152. When disassembling the jetting tool 100, the spring sleeve164 retains the spring 162 and spring follower 214 within the springhousing 152 while the swivel housing 116 is removed.

In one embodiment a jetting housing 196 is provided around the bypassvalve 100. The jetting housing 196 displaces annular space when thebypass valve 100 is to be used in a bore, such as that of a riser,having a sufficiently large inner diameter that annular fluid velocitywould be lost if the jetting tool 100 were used without the jettinghousing 196. By reducing the annular area, fluid velocity through thesecond outlet 132 into the annulus 104 may be maintained at a rate thatis effective for removing debris or circulating fluid. Jetting housings196 having different outer diameters may be available and the choice ofsize is typically based upon the diameter of the casing to be cleaned.Referring to FIGS. 2 and 3, the jetting housing 196 includes a pluralityof jetting ports 198. When the second outlet 128 is open, the jettingports 198 focus a stream of fluid toward the casing 106 of the wellbore108 in a direction substantially perpendicular to the axial throughpassage 124. As the fluid exits the jetting ports 198, the direction ofthe stream of fluid will be affected by fluid circulation in the annulus104 fluid pressure in the annulus 104, as well as the geometry of thejetting port exits. While the fluid is directed toward the casing 106,it will be appreciated by a person of skill in the art that the fluiddirection will not be precisely pointed at a point on the casing, butrather a general area of the casing 106. In one embodiment, the jettinghousing 196 includes a plurality of tangent jetting ports 212, as can beseen in FIG. 3. Tangent jetting ports 212 direct fluid flow in adirection substantially tangent to the flow of fluid out of the jettingports 198. As with the jetting ports 198, fluid flow out of the tangentjetting ports 212 is affected by a variety of factors including fluidcirculation in the annulus 104 fluid pressure in the annulus 104, aswell as the geometry of the tangent jetting port exits. In oneembodiment, the jetting housing 196 is rotationally retained on theouter housing 110. In one embodiment, tangent jetting ports 212 rotatethe jetting housing 196 about the outer housing 110.

When lowered downhole on the drill string, the jetting tool 100 is in afirst position, as depicted in FIGS. 1 and 5. In this position, therecess 202 of the indexing mandrel 170 is positioned inside the secondoutlet 128. As depicted in FIG. 1, the seal ring 180 is located abovethe second outlet 128 while the o-ring 204 is positioned below thesecond outlet 128 to prevent fluid communication between the throughpassage 176 and the annulus 104. Returning to FIGS. 1 and 5, fluid maycontinue to flow through the through passage 176 defined by the indexhousing 168 and the through passage 156 defined by the spring housing152.

Referring to FIG. 6, when it is desired to actuate the jetting tool 100,a ball 250 is dropped through the drill string and circulated until itreaches the jetting tool 100. The ball 250 has a ball radius 252, whichis less than the outer housing radius 232 and greater than the landingsection radius 240, thus permitting the ball 250 to continue tocirculate through the jetting tool 100 until it comes to rest atop thelanding section 190. The ball 250 prevents further fluid flow throughthe bore 238, 156 of the index housing 168, spring 216, and springhousing 152. As the fluid pressure is increased, the ball seat 148 andindex housing 168 are pushed downward against the upward force of thespring 216. The indexing groove 200 on the indexing mandrel 170interfaces with the indexing pin 146 to direct the position of theindexing mandrel 170 within the outer housing 110.

The indexing groove path 262 is depicted in FIG. 4. When the jettingtool 100 is in the first position, the indexing pin 146 is located in afirst groove location 260. Referring to FIG. 6, after the ball 250 isseated on the ball seat 148, fluid pressure is increased until the ballseat 148 and indexing mandrel 170 are driven downward against the forceof the spring 216. As the indexing mandrel 170 moves downward within theouter housing 110, the indexing pin 146 follows the indexing groove path262 until it has reached a first groove wall 264. Upon contacting thefirst groove wall 264, the indexing pin 146 continues a path parallel tothe first groove wall 264 until it has shouldered against second groovelocation 266. The outer housing 110 is rotationally fixed by the drillstring. The swivel ring 144 is rotated within the outer housing 110 asthe indexing pin 146 follows the indexing groove path 262. When theindexing pin 146 is shouldered against the second groove location 266,the jetting tool 100 is in a corresponding second position, shown inFIG. 6.

In the second position, the ball 250 remains seated atop the landingsection 190 of the ball seat 148. The indexing mandrel 170 and ball seat148 have moved a sufficient distance downward to open the second outlet128, providing fluid communication from the through passage 124 to theannulus 104. So long as the fluid flow remains sufficient to providepressure to the ball 250 and the index housing 168 to overcome theupward force of the spring 216, the jetting tool 100 will remain in thesecond position.

Referring to FIGS. 6 and 7, when the flow drops to below a predeterminedflow rate corresponding to a predetermined fluid pressure, the spring216 will push the index housing 168 upward. The indexing pin 146continues to follow the indexing groove path 262 and contacts a secondgroove wall 268. The indexing pin 146 follows the incline of the secondgroove wall 268 to position the indexing mandrel 170 within the outerhousing 110. The indexing mandrel 170 continues to move upward until theindexing pin 146 shoulders against a third groove location 270. When theindexing pin 146 is in the third groove location 270, the jetting tool100 is in a corresponding third position, shown in FIG. 7.

In the third position, the ball 250 remains seated atop the landingsection 190 of the ball seat 148. The second outlet 128 is closed,resulting in no fluid communication from the through passage 124 to theannulus 104 and no flow through the through passage 124 to the firstoutlet 208.

The fluid pressure may be increased to cycle the indexing mandrel 170 toa fourth position, in which the indexing pin 146 is shouldered against afourth groove location 272 longitudinally located along the indexingmandrel 170 between the second groove location 266 and the third groovelocation 270. So long as the fluid pressure does not exceed apredetermined pressure sufficient to deform the ball 250, decreasing thefluid pressure again will return the indexing mandrel 168 to the thirdposition, wherein the indexing pin 146 is shouldered against anotherthird groove location 270. Increasing pressure when the ball 250 is inthe third position for the second time will return the indexing mandrel170 to a second position in which the second outlet 128 is open. Thiscycle may be continued until the indexing pin 146 has traversed theindexing groove path 262 any number of times.

When the jetting operation is completed, the jetting tool 100 is cycledby increasing and decreasing fluid pressure on the ball 250 until theindexing pin 146 is again in the fourth groove location 272. Thepressure may then be increased to a predetermined pressure sufficient toshear the ball 250 through the bottom 194 of the ball seat 148, as shownin FIG. 8. The ball 250 is then forced downward through the throughpassage 238 of the index housing 168 and the through passage 156 of thespring housing 152. The ball 250 is caught in a downstream ball catcher122. When the ball 250 is released from the ball seat 148, the fluidpressure counteracting the spring force is relieved and the spring 216pushes the index housing 168 and the ball seat 148 upward. The indexinggroove 200 and pin 146 interact to reposition the indexing mandrel 170in the first position in which the second outlet 128 is closed and fromwhich the entire process may be performed again.

Referring to FIG. 1, the ball catcher 122 includes a ball catcher sub234 within which a ball catcher tube 236 is retained. A trap finger 238is provided near the top end 242 of the ball catcher tube 236. The topend 242 of the ball catcher tube 236 may be provided with slots 276. Thetrap finger 238 is pivotally retained to the ball catcher tube 236 nearthe top end 242 along a pivot edge 244. A torsion spring 246 biases thetrap finger 238 toward a “closed” position. As shown in FIG. 1, a freeedge 248 is rotatable within the ball catcher sub 234. The trap finger238 has a length 254 such that the trap finger 238 free edge 248 cantravel through slot 276 and is caught on an edge of the slot 276 beforeopening in an upward position. A stopper 178 may be included near thefree edge 248 to aid in catching the slot edge before over-traveling.When the ball 250 is discharged from the ball seat 148, the ball 250pushes the free edge 248 downward and enters the ball tube 236. Once theball 250 has cleared the trap finger 238, the torsion spring 246 movesthe trap finger 238 back to the closed position.

The ball catcher tube 236 has an outer diameter less than the innerdiameter of the ball catcher sub 234, defining a ball catcher annulus274. The ball catcher tube 236 is also provided with a number of holes258 though the wall of the tube 236 providing fluid communication fromthe though passage of the ball catcher tube 236 to the ball catcherannulus 274. If reverse circulation is desired, the holes 258 and ballcatcher annulus 274 allow fluid flow around any balls 250 retained inthe ball catcher tube 236 and to the tools above the ball catcher 122.Any balls 150 in the ball catcher tube 236 that are forced upward by thereverse circulation are retained by the trap finger 238. Any force onthe trap finger 238 by retained balls 250 will reinforce the force ofthe torsion spring 246 in pushing the free edge 248 against the slotedge of the ball catcher tube 236, thereby preventing the loss of balls250 from the ball catcher 122. The ball catcher tube 236 may be sized toaccommodate any number of balls 250. For example, in one embodiment, theball catcher tube 126 holds six balls 250.

The jetting tool 100 can be used to clean the inner surface of a casingand/or a blowout preventor (BOP). To perform a cleaning operation, thejetting tool 100 is assembled on a work string and lowered into thewellbore 108 to a location to be cleaned. The index housing 168 is in afirst position relative to the outer housing 110, as shown in FIG. 5,and the second outlet 128 through the outer housing 110 is closed off bythe index housing 168. The ball 250 is dropped into the axial throughpassage 102 of the work string and is circulated through the work stringuntil the it reaches the ball seat 148 of the jetting tool 100. When theball 150 reaches the ball seat 128, it is directed to a landing section190 where it prevents fluid from flowing through the index housing 168and spring housing 152 as well as the lower work string tools (notshown). Fluid continues to be pumped at a predetermined rate into thethrough passage 102 of the work string, thereby applying pressure to theball 250. This pressure works against the upward force of the spring216. As the pressure on the ball 250 increases, the index housing 168 islowered relative to the outer housing 110 until the index housing 168reaches a second position, shown in FIG. 6. When the index housing 168is in the second position, the second outlet 128 through the outerhousing 110 is open. The fluid that is being pumped into the axialthrough passage is then directed through the second outlet 128 and thejetting ports 198 at a pressure sufficient to clean the casing and/orBOP. The jetting tool 100 may be rotated by rotating the work string todirect fluid flow from the jetting ports 198 at a circumferential areaof the casing or BOP. The jetting tool 100 may be raised and/or loweredby raising and/or lowering the work string to direct flow from thejetting ports 198 at a longitudinal area of the casing or BOP. Aspreviously discussed, the jetting housing 196 may be rotationallyretained on the outer housing 110 and tangential jetting ports 212utilized to rotate the jetting housing 196 to clean a circumferentialarea of the casing and/or BOP.

When a location of the casing and/or BOP has been cleaned, fluidpressure through the axial through passage 124 may be reduced. As thepressure is reduced to a pressure insufficient to overcome the springforce, the spring 216 pushes the index housing 168 upward relative tothe outer housing 110 to a third position, shown in FIG. 7. The secondoutlet 128 through the outer housing 110 is closed when the indexhousing 168 is in the third position.

The pressure may be increased again to a predetermined pressure that issufficient to overcome the spring force but that is insufficient todeform the ball 250. This drives the index housing 168 to a fourthposition. From the fourth position, the fluid pressure may be decreasedagain so that the spring 216 forces the index housing 168 into anotherfirst position. Increasing the pressure from this third position willforce the index housing 168 into another second position in which thesecond outlet 128 is again open and additional cleaning activities maybe performed. If such additional cleaning activities are not desired,from the fourth position, the fluid pressure may be increased by anadditional amount sufficient to shear the ball 250 from the ball seat148. When the ball 250 has been sheared from the ball seat 148, thespring 216 will force the index housing 168 into another first positionand the jetting tool may be re-actuated by dropping another ball 250.The sheared ball 250 is circulated through the remainder of the jettingtool 100 and is caught by the ball catcher 122. As previously discussed,if recirculation of the fluid is desired, the ball catcher 122 willretain any sheared balls 250 previously caught in the ball catcher 122.

Referring to FIG. 9, in another embodiment, a downhole bypass valve 300is used to selectively divert fluid that is flowing down the drillstring bore 302 to the annulus 304 between the drill string and thecasing 306 of a wellbore 308. The bypass valve 300 includes an outerhousing 310, a spring-loaded mandrel 368, and a cantilever-type ballseat collet assembly 410 defining a tubular assembly having an inlet 406and a first outlet 408.

The outer housing 310 defines an outer housing through bore 324 withinwhich the spring-loaded mandrel 368 and the collet assembly 410 arelocated. The outer housing 310 has a top sub 326 provided at a top end312, wherein the top sub 326 includes a threaded box 314 to couple to anupper drill string component 316. The top sub 326 is coupled to a portedseal housing 328 at a lower end 330. The ported seal housing 328 has oneor more radially extending ports 332 extending from the outer housingthrough bore 324 to the annulus 304, defining a second outlet. A swivelhousing 334 is coupled to a lower end 336 of the ported seal housing328. As shown more clearly in FIG. 10 a, the coupling of the swivelhousing 334 and the ported seal housing 328 provides an upper shoulder338 at the lower end 336 of the ported seal housing 328. A lowershoulder 340, formed in the swivel housing 334, is spaced apart from theupper shoulder 336 to form an inner recess 342 within which a swivelring 344 is retained. The swivel ring 344 includes at least one indexingpin 346 extending radially into the through bore 324 defined by theouter housing 310. While the swivel ring 344 is axially retained by theupper and lower shoulders 338, 340, the swivel ring 344 is notrotationally retained to the outer housing 310. Thus, the swivel ring344 may rotate within the confines of the upper and lower shoulders 338,340. Returning to FIG. 9, along a middle portion 350 of the swivelhousing 334, a spring housing 352 is coupled thereto. As shown moreclearly in FIG. 10 c, a lower portion 354 of the swivel housing 334protrudes axially within a through bore 356 defined by the springhousing 352 and has a recess formation 358 in an inner surface 359 atits lower end 360. The lower portion 354 of the swivel housing 334 isspaced apart from the corresponding portion of the spring housing 352such that a small gap 362 is created. Within this small gap 362, aspring sleeve 362 is coupled to the spring housing 352. As will beexplained below, the spring sleeve 364 is included primarily to aid inthe assembly and disassembly of the bypass valve 300. Returning again toFIG. 9, the spring housing 352 is provided with external threads 320 atlower end 318 to couple to a lower drill string component 322.

As previously stated, the spring-loaded mandrel 368 is located withinthe outer housing 310. The spring-loaded mandrel 368 includes anindexing mandrel 370 coupled at a lower end 372 to a shoulder sub 374 todefine a mandrel through bore 376. As shown in FIG. 10 b, the throughbore 376 has a mandrel bore radius 378. A bonded seal member 380 islocated above a shoulder formation 382 in the outer surface 384 of theindexing mandrel 370. A retaining ring 386 may be secured to theindexing mandrel 370 such that it is spaced apart from the shoulderformation 382 to maintain the bonded seal member 380 in a position nearthe upper end 387 of the indexing mandrel 370. The bonded seal member380 includes a pair of resilient outer seals 388, 390, which seal theinterface between the inner surface 392 of the ported seal housing 328and the outer surface 394 of the bonded seal member 380. An o-ring 396seals the interface between an inner surface 398 of the bonded sealmember 380 and the outer surface 384 of the indexing mandrel 370. Belowthe shoulder formation 382, a recess 402 is formed in the outer surface384 of the indexing mandrel 370. An o-ring 404 seals the interfacebetween the outer surface 384 of the indexing mandrel 370 and the innersurface 392 of the ported seal housing 328 below the recess 402.Returning to FIG. 9, an indexing groove 400 is formed into the outersurface 384 of the indexing mandrel 370 between the o-ring 404 and alower end 372 of the indexing mandrel 370. The indexing pin 346, coupledto the outer housing 310, is positioned within the indexing groove 400.The function of the indexing groove 400 and the indexing pin 346 isdescribed in greater detail below.

The ball seat collet assembly 410 includes a collet member 412, a springfollower 414 and a spring 416. As will be described, the collet assembly410 has limited axial mobility within the through bore 324 of the outerhousing 310. The spring 416 is located within the through bore 356defined by the spring housing 352. A shoulder formation 418 in the innersurface 420 of the spring housing 352 near the lower end 318 providessupport to a lower end 422 of the spring 416. As can be seen moreclearly in FIG. 10 c, the spring follower 414 has a lower shoulder 424that is seated atop an upper end 426 of the spring 416. The colletmember 412 has a lower end 428 that is seated atop an upper shoulder 430of the spring follower 414. From the collet member lower end 428,several cantilevered collet arms 432 extend upward. A collet head 434 islocated at an upper end 436 of each collet arm 432. In the positionshown in FIG. 9, each collet head 434 is biased outward by thecorresponding cantilevered collet arm 432 to contact the inner surface359 of the lower portion 354 of the swivel housing 334. The collet heads434 form a collet through bore 438 having a collet inner radius 440.

When the bypass valve 300 is assembled, the spring 416 is lowered intothe spring housing 352 and the spring follower 414 is placed atop thespring 416. The swivel housing 334 couples to the spring housing 352.However, the length of the spring 416 when loaded only with the springfollower 414 would extend beyond the lower end 360 of the lower portion354 of the swivel housing 334 when the swivel housing 334 is coupled tothe spring housing 352. Instead of loading the spring 416 with theswivel housing 334 while coupling to the spring housing 352, the springsleeve 364 is coupled to the spring housing 352 to preload the spring416, through the spring follower 414, against a lower shoulder 366. Thesmaller size of the spring sleeve 364 makes it easier to couple to thespring housing 352 while simultaneously preloading the spring 416. Thelarger swivel housing 334 may then be simply coupled to the springhousing 352. When disassembling the bypass valve 300, the spring sleeve364 retains the spring 362 and spring follower 414 within the springhousing 352 while the swivel housing 334 is removed.

In an alternative embodiment a jetting housing (not shown) may beprovided around the bypass valve 300. The jetting housing displacesannular space when the bypass valve 300 is to be used in a bore, such asthat of a riser, having a sufficiently large inner diameter that annularfluid velocity would be lost if the bypass valve 300 were used alone. Byreducing the annular area, fluid velocity through the ports 332 into theannulus 304 may be maintained at a rate that is effective for removingdebris or circulating fluid.

When lowered downhole on the drill string, the bypass valve 300 is in afirst position, as depicted in FIG. 9. In this position, the recess 402of the indexing mandrel 370 is positioned inside the ports 332. Asdepicted in FIG. 10 c, the outer seals 388, 390 of the bonded seal ring380 are located above the ports 332 while the o-ring 404 is positionedbelow the ports 332 to prevent fluid communication between the throughbore 376 and the annulus 304. Returning to FIG. 9, fluid may continue toflow through the through bore 376 defined by the spring loaded mandrel368 and the through bore 356 defined by the spring housing 352. In thefirst position, the collet inner radius 440 is slightly smaller than themandrel radius 378 (shown in FIGS. 10 c and 10 b, respectfully).

Referring to FIG. 11, when it is desired to actuate the bypass valve300, a ball 450 is dropped through the drill string and circulated untilit reaches the bypass valve 300. The ball 450 has a ball radius 452,which is less than the mandrel bore radius 378 and greater than thecollet inner radius 440, thus permitting the ball 450 to continue tocirculate through the bypass valve 300 until it comes to rest atop thecollet heads 434 of the collet assembly 410. The ball 450 preventsfurther fluid flow through the bore 438, 456 of the collet assembly 410,spring 416, and spring housing 352. As the fluid pressure is increased,the collet assembly 410 is pushed downward against the upward force ofthe spring 416. The increased fluid pressure within the axial throughbore 376 and the lower pressure outside of the mandrel 368 causes thespring loaded mandrel 368 to move downward as well. The indexing groove400 on the indexing mandrel 370 interfaces with the indexing pin 346 todirect the position of the spring loaded mandrel 368 within the outerhousing 310.

The indexing groove path 462 is depicted in FIG. 15. When the bypassvalve 300 is in the first position, the indexing pin 346 is located in afirst groove location 460. Referring to FIGS. 12 and 15, after the ball450 is seated on the collet heads 434, fluid pressure is increased untilthe collet assembly 410 is driven downward against the force of thespring 416. The spring loaded mandrel 368 is also pushed downward by theincreased fluid pressure within the axial bore 376. As the spring loadedmandrel 368 moves downward within the outer housing 310, the indexingpin 346 follows the indexing groove path 462 until it has reached afirst groove wall 464. Upon contacting the first groove wall 464, theindexing pin 346 continues a path parallel to the first groove wall 464until it has shouldered against second groove location 466. The outerhousing 310 is rotationally fixed by the drill string. The spring loadedmandrel 368 is rotated within the outer housing 310 as the indexing pin346 follows the indexing groove path 462. When the indexing pin 346 isshouldered against the second groove location 466, the bypass valve 300is in a corresponding second position, shown in FIG. 12.

In the second position, the ball 450 remains seated atop the colletheads 434. The spring loaded mandrel 368 has moved a sufficient distancedownward to open the ports 332, providing fluid communication from thethrough bore 324 to the annulus 304. So long as the fluid flow remainssufficient to provide pressure to the ball 450 and the collet assembly410 to overcome the upward force of the spring 416, the bypass valve 300will remain in the second position.

Referring to FIGS. 13 and 15, when the flow drops to below apredetermined flow rate corresponding to a predetermined fluid pressure,the spring 416 will push the collet assembly 410 upward. The colletassembly 410 in turn pushes the spring loaded mandrel 368 upward. Theindexing pin 346 continues to follow the indexing groove path 462 andcontacts a second groove wall 468. The indexing pin 346 follows theincline of the second groove wall 468 to rotate the spring loadedmandrel 368 within the outer housing 310 as it continues to move upwarduntil the indexing pin 346 shoulders against a third groove location470. When the indexing pin 346 is in the third groove location 470, thebypass valve 300 is in a corresponding third position, shown in FIG. 13.

In the third position, the ball 450 remains seated atop the collet heads434. The ports 332 remain open, providing fluid communication from thethrough bore 324 to the annulus 304. In this position, the fluid can bereverse circulated at any desired rate. Circulation can be maintained upto a predetermined rate at which the fluid pressure would overcome thespring force once again. In the third position, multiple batches ofvarious fluids can be circulated, depending upon the viscosity anddensity of the fluids, so long as the predetermined rate is notexceeded.

The fluid pressure may be increased to cycle the spring loaded mandrel368 to the second position, in which the indexing pin 346 is shoulderedagainst another second groove location 466. Decreasing the fluidpressure again will return the spring loaded mandrel 368 to the thirdposition, wherein the indexing pin 346 is shouldered against anotherthird groove location 470. This cycle may be continued until theindexing pin 346 has traversed the indexing groove path 462 to shoulderagainst a final third groove location 470, corresponding to the thirdposition.

Referring to FIGS. 14 and 15, to close the bypass valve 300, the fluidpressure may be increased when the indexing pin 346 is shoulderedagainst the final third groove location 470. As previously described, asthe fluid pressure is increased, the collet assembly 410 and mandrel 368are driven downward against the force of the spring 416. This time,however, the indexing pin 346 is directed along the indexing groove path462 until it shoulders against a final groove location 472. The finalgroove location 472 corresponds to a fourth position of the springloaded mandrel 368 that is farther downhole, relative to the outerhousing 310, than in the first, second, or third positions. In thefourth position, the collet assembly 410 is driven downward against theforce of the spring 416 until the collet heads 434 are received intocorresponding recess formations 358 in the lower portion 354 of theswivel housing 334. Once the collet heads 434 spring outward into therecess formations 358, the collet inner radius 440 is enlarged such thatit is larger than the ball radius 452. The ball 450 is then forceddownward through the bore 438 of the collet assembly 310 and the bore356 of the spring housing 352. The ball 450 will be caught in adownstream ball catcher (not shown). When the ball 450 is released fromthe collet heads 434, the fluid pressure counteracting the spring forceis relieved and the spring 416 pushes the collet assembly 410 upward.The collet assembly 410 in turn pushes the spring loaded mandrel 368upward. The indexing groove 400 and pin 346 interact to reposition thespring-loaded mandrel 368 in the first position in which the ports 332are closed and from which the entire process may be performed again.

While the claimed subject matter has been described with respect to alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that other embodiments can bedevised which do not depart from the scope of the claimed subject matteras disclosed herein. Accordingly, the scope of the claimed subjectmatter should be limited only by the attached claims.

1. An apparatus for cleaning a wellbore casing comprising: an outerhousing having an axial through passage between an inlet and a firstoutlet wherein the inlet and the first outlet are adapted for connectionin a work string, the outer housing having a second outlet extending ina direction generally transversely of the through passage; an indexmandrel slidably located within the outer housing and having an axialbore extending therethrough, the index mandrel being movable relative tothe outer housing between a first position in which the second outlet isclosed and a second position in which the second outlet is open; a ballseat located on an upper end of the index mandrel; a spring locatedwithin the outer housing and biasing the index mandrel toward the firstposition; a ball retainable on the ball seat to prevent flow from theinlet to the first outlet; and wherein application of a first pressureon the ball forces the index mandrel against the spring into the secondposition and reduction of said first pressure permits return of theindex mandrel to the second position.
 2. The apparatus of claim 1,further comprising: an indexing pin retained on an inner surface of theouter housing; wherein the index mandrel has an indexing groove in anouter surface; and wherein the indexing pin cooperates with the indexinggroove to position the index mandrel in the first position and thesecond position.
 3. The apparatus of claim 2, wherein the index mandrelhas a third position, between the first position and the secondposition, in which the second outlet is closed.
 4. The apparatus ofclaim 1, further comprising: a jet housing around the outer housing, thejet housing including a plurality of nozzles in fluid communication withthe second outlet and positioned to direct fluid received from thesecond outlet in a direction substantially perpendicular to the axialthrough passage.
 5. The apparatus of claim 4, wherein the jet housingfurther comprises: a plurality of nozzles in fluid communication withthe second outlet and positioned to direct fluid received from thesecond outlet in a direction substantially tangent to the jet housing.6. The apparatus of claim 5, wherein the jet housing is rotatable aboutthe outer housing.
 7. The apparatus of claim 1, wherein the ball isdeformable to be pushed through the ball seat and discharged through thefirst outlet.
 8. The apparatus of claim 1, further comprising: a ballcatcher sub positioned below the outer housing, the ball catcher subcomprising: a ball catcher housing having a ball catcher axial throughpassage between a ball catcher inlet and a ball catcher outlet whereinthe ball catcher inlet and the ball catcher outlet are adapted forconnection in a work string; a trap finger pivotally retained within theball catcher housing, wherein the trap finger is pivotable to receivethe ball when discharged from the first outlet; a ball catcher tuberetained within the ball housing and having a length and an innerdiameter sufficient to hold a plurality of balls; and wherein an annulusis formed between the ball catcher tube and the ball catcher housingsufficient for fluid to be communicated through the ball catcher sub. 9.The apparatus of claim 8, wherein the trap finger pivots downward toreceive the ball within the ball catcher tube and cannot pivot upwards,thereby preventing the ball from escaping the ball catcher tube whenfluid is reverse circulated through the axial through passage.
 10. Theapparatus of claim 8, wherein the ball catcher tube has a plurality ofholes therein to communicate fluid from the ball catcher tube to theannulus.
 11. A method of cleaning an inner surface of a casing in awellbore comprising: lowering a jetting tool on a work string into thewellbore to a desired location, wherein the jetting tool has an outerhousing with an axial through passage between an inlet and a firstoutlet, the outer housing also having a second outlet substantiallytransverse to the axial through passage, and an index housing slidinglyretained within the outer housing in a first position such that thesecond outlet is closed, the index housing having a ball seat on anupper end and being biased toward the first position; dropping a ballinto the axial through passage to rest on the ball seat, therebypreventing fluid flow between the inlet and the first outlet of theaxial through passage, causing fluid pressure to force the index housingto a second position wherein the second outlet is open; circulatingfluid from the axial through passage and the second outlet at a fluidpressure sufficient to clean the casing; decreasing the fluid pressureto return the index housing to the first position; increasing the fluidpressure to move the index housing to a third position wherein thesecond outlet is closed; and wherein the increased fluid pressure issufficient to shear the ball from the ball seat, thereby reducing thefluid pressure on the index housing causing it to return to the firstposition.
 12. The method of claim 11, further comprising: rotating thejetting tool while circulating the fluid to direct the circulating fluidcircumferentially around the inner surface of the casing.
 13. The methodof claim 12, further comprising: raising and lowering the jetting toolin the wellbore while circulating the fluid to clean a longitudinal areaof the inner surface of the casing.
 14. The method of claim 13, furthercomprising: positioning the jetting tool within the blowout preventor;and circulating the fluid from the axial through passage and the secondoutlet at a fluid pressure sufficient to clean the blowout preventor.15. The method of claim 11, further comprising: catching the ball in aball catcher located below the index housing.
 16. The method of claim15, further comprising: reverse circulating the fluid through the axialthrough passage; and retaining the ball in the ball catcher with a trapfinger during reverse circulation.
 17. A method of opening and closingan outlet through a side of a cylindrical outer housing of a jettingtool in a wellbore, the method comprising: biasing the index housing toan upward position within the outer housing in which the index housingis blocking the fluid outlet through the side of the outer housing;dropping a ball to seal against a ball seat located at the upper end ofthe index housing and block fluid flow through the jetting tool; forcingthe index housing to a lower position inside the outer housing as aresult of increased pressure behind the ball, wherein the fluid outletthrough the side of the outer housing is open; reducing the fluidpressure on the ball to permit the biasing of the index housing towardsthe upward position, wherein the fluid outlet through the side of theouter housing is closed; and increasing the fluid pressure on the ballto a pressure sufficient to shear the ball through the ball seat,thereby permitting the index housing to return to the upward position.18. The method of claim 17, wherein the fluid pressure is increased anddecreased a quantity of times to open and close the fluid outlet throughthe side of the outer housing before increasing the fluid pressuresufficient to shear the ball.
 19. The method of claim 18, furthercomprising: dropping a second ball after shearing the first ball to sealagainst the ball seat and block fluid flow through the jetting tool;repeating the forcing, repeating, and increasing steps.